A coordinate plane can help you examine the different properties of a shape. For
example…
The rectangle ABCD has vertices at A(-6, 0), B(1, 0), C(1, 3) and D(-6, 3). What is
the area of the rectangle?
Step 1: Draw the Shape
Use the coordinates to graph the rectangle on the coordinate plane.
Step 2: Determine the area
The formula for finding the area of a rectangle is
a = (length) (width)
We can determine the length and width by counting the units on the graph.
area = 21 units
Step 3: Check your answer
You can check your answer by counting the units within the rectangle.
We can use the same graph to find the perimeter of the rectangle.
perimeter = 2 ( length + width )
p = 2( 7 + 3 )
p = 20